This invention deals with improvements in occlusive and semi-occlusive dressings that promote healing of ulcerated tissue and other lesions in the skin.
Of the many dressings currently on the market that use hydrocolloids most are based principally on polymers such as polyisobutylene (PIB) alone or in combination with other polymers such as styrene--isoprene copolymers which are loaded with various gums natural origin or synthetic substances such as superabsorbents to create wet tack and to give a degree of absorption.
Although some of the currently available hydrocolloid based dressings have proved effective in clinical settings they suffer from a number of defects. These defects include messiness resulting from saturation with and overflow of wound exudate and difficulty in cleaning up, difficulty in removal from the wound area and leakage of wound exudate when first applied. A further difficulty with some of these hydrocolloid dressings is the generation of unpleasant odors. Yet another difficulty is the generation of allergic reactions due to the presence of allergens. For leg ulcer patients allergic reactions can be a serious problem as they have often been sensitized by exposure to many medicaments over many years.
A fundamental difficulty with dressings based on PIB alone or in combination with styrene---isoprene copolymers that contributes to, or causes the aforementioned difficulties, is the inability of such wound dressings to absorb fluids exuded from wounds such as leg ulcers at a rate commensurate with the rate at which the body produces such fluids.
There is a need for a hydrocolloid wound dressing that is so designed and constructed that it can absorb wound exudate at a rate more nearly commensurate with the rate at which the body produces such fluids. Such a wound dressing would eliminate or ameliorate problems with current hydrocolloid wound dressings such as messiness, saturation and overflow, difficulty in removal and cleanup and odor generation. There is a further need for a hydrocolloid wound dressing that does not produce allergic reactions, particularly in patients that have been sensitized.